Electric switch



P 10, 1957 F. R. EDGARTON 2,806,104

ELECTRIC SWITCH Filed Jan. 14, 1955 2 Sheets-Sheet l INVENTOR. FRANK R. EDGARTON ATTORNEY Sept. 10, 1957 F. R. EDGARTON ELECTRIC SWITCH 2 Sheets-Sheet 2 Filed Jan. 14, 1955 Mu n0 ml? 7% m 07% w 1 m 1 i 3 9 INVENTOR.

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FRANK R. EDGARTON ATTORNEY United States Patent @fiice Patented Sept. 10, 1957 ELECTRIC SWITCH Frank R. Edgarton, Webster, N. Y., assignor, by mesne assignments, to General Dynamics Corporation, a corporation of Delaware Application January 14, 1955, Serial No. 481,908

3 Claims. (Cl. 200104) The present invention relates to electric switch constructions.

Many different forms of multi-contact electric switches are used in the telephone industry. Many of such switches may include one or more movable switch brushes, each adapted to successively engage selected ones of a plurality of relatively fixed electric contact elements as the brush or brushes are moved. The plurality of contact elements are generally grouped in socalled contact banks that are positioned in the path of movement of the switch brushes that are adapted to successively and selectively engage respective ones of the contact elements. Prior to this invention the banks of contact elements were more or less permanently secured to the switch structure in the positions to be engaged by the switch brushes as the switch brushes are moved. Such an arrangement is sometimes inconvenient when wiring the switch in a particular circuit since it requires the entire switch assembly to be handled when making the electrical connections to the switch contacts.

It is a principal object of the present invention to provide an improved multi-contact switch.

It is another object of the present invention to provide an improved multi-contact switch having a removable contact bank assembly.

In a preferred embodiment of the invention, a plurality of removable contact banks are provided to be each associated with a respective one of a plurality of movable switch brushes adapted to be moved in step-bystep fashion to successive contact positions in an arrangement similar to either of the so-called minor switches or rotary switches although it should be understood that the removable contact bank feature of the invention may be incorporated with other types of multicontact switches having various modes of operation.

Further objects, features, and the attending advantages of the invention will be apparent with reference to the following specification and drawings in which:

Fig. 1 is a top plan view of a so-called minor switch embodying the invention,

Fig. 2 is a fragmentary end view of the switch as see from the lower end of Fig. 1 of the drawings,

Fig. 3 is a side elevation of the contact bank used with the switch of the invention,

Fig. 4 is a top plan view of the contact bank shown in Fig. 3,

Fig. 5 is an end view of the right hand end of the contact banks as was shown in Fig. 3,

Fig. 6 is a side elevation of the contact bank clip structure,

Fig. 7 is an end view taken to the left of Fig. 6,

Fig. 8 is an end view taken to the right of Fig. 6,

Fig. 9 is a view showing the contact bank about to be inserted in the clip structure, and

Fig. 10 is another view showing a contact bank as received and supported in the clip structure.

Referring to Figures 1 and 2 of the drawings, the electric switch elements are all mounted on a frame member 10 formed as a stamping from suitable sheet metal. A switch operating drive magnet 11 of the electric coil type and a switch release magnet 12, also of the electric coil type, are mounted in the positions as shown. The drive magnet 11 has an armature 13 pivoted at 14 on a pivot extending in a plane at right angles to the general plane of the frame member 10. The armature 13 and pivot 14 are secured to the magnet frame 15 which, in turn, is secured to the switch frame 10 in any suitable fashion. A coil spring 16 is connected at one end to a frame member 17 secured to the magnet frame 15, and is joined at the other end 18 to a portion of the armature 13 in a manner to normally pivot the armature 13 about the pivot point 14 in a counterclockwise direction away from the magnet 11. The other end of the armature 13 is provided with a driving pawl 20 adapted to engage a ratchet cog 21 secured on a switch drive shaft 22. The switch drive shaft 22 is journaled for rotation on the base member 10 and extends perpendicularly to the general plane member 10. The armature 13 also has an escapement portion 23 adapted to engage projections, such as shown at 24 and 25, of a switch positioning cog member 26 which is likewise secured to the switch drive shaft 22. The drive gear 27 is also secured to the switch drive shaft 22 and engages the rack gear arm 28 in a manner such that the counterclockwise rotation of the drive shaft 22 will cause the gear rack arm 28 to move in a direction to the right of the drawings.

The rack arm 28 is slidably journaled upon a suitable frame member 29 having studs 30 and 31 received within the slot 32 of the rack member 28. As the drive magnet 11 is alternately energized and deenergized, the lever arm 13 is alternately drawn towards the magnet 11 to the position shown in the drawings, and then released to cause the driving pawl 20 and escapement member 23 to impart step-wise counterclockwise rotation to the switch drive shaft 22, as should be readily understood. The resulting step-wise movement of the rack arm 28 is thus controlled to be moved in uniform incremental amounts as determined by the spacing between the cog members 24 and 25.

The rack member 28 is provided with an integral bracket 3-5 upon which is supported in insulated relation a plurality of switch contact brushes, such as the four brushes shown at 36, 37, 38 and 39. As more clearly shown by the end view of Fig. 2, each brush member, such as the brush member 39, is formed with bifurcated spring portions 40 and 41 which are shaped to provide contact at their end portions only with a respective one of the bare wire contacts 42 or 43, etc., as the rack 28 and switch brushes are moved to the right of the drawings in response to the stepping operation of the switch drive mechanism including the magnet 11 and associated ratchet mechanism.

In order to release the switch for return of the switch brusl es to their normal position as shown in solid lines, the switch release magnet 12 is energized to pivot its armature 50 about the pivot point 51 in a counterclockwise direction. The free end of the armature 50 engages an upstanding end 52 of the release pawl 53 which is pivoted at 54 to the main switch frame 10. The counterclockwise movement of the release magnet armature 50 causes a clockwise movement of the release pawl 53 to disengage the release or retaining pawl from the ratchet 21. A biasing coil spring (not shown) is connected between the switch drive shaft 22 and the frame 10 in a manner to rotate the switch drive shaft 22 in a clockwise direction and return the gear rack 28 and the switch carriage 35 and brushes 3639 to their normal solid line positions whenever the retaining pawl 53 is disengaged from the ratchet gear 21. Of course, a suit- 3 able stop mechanism, not shown in detail, is provided to limit the movement of the switch carriage to the left of the drawing to the solid line position as shown.

Contact springs, generally shown at i.60, are provided to be opened .each time the release magnet 12 is energized in a manner to cause the retaining pawl .53'to be moved clockwise for releasing and restoring the .switch to normal. Similarly, a plurality of contact springs, generally shown at 61, are provided .to be operated by the lever mechanism .62 that is pivoted at .63 on the frame and adapted to be operated by the escapement end 23 of the drive magnet armature 13. In addition, contact springs, generally shown at 64, are also provided to be opened each time the drive magnet armature 13 is attracted by the drive magnet 11 as controlled by the pin 65 engaging one of the springs of the contact assembly 64. All of the various contact spring assemblies 60, 61 and 64 are provided for specialized circuit functions which do not form a part of the present invention and maybe added or omitted to the present switch structure without departing from the spirit of the invention.

As has been earlier described, the movable switch brushes, such as any one of the brushes 36-39, are adapted to selectively engage respective ones of a plurality of bare wire switch bank contacts, such as shown at 42 and 43. In the illustrated embodiment of the invention, the bare wire contacts are arranged in groups of eleven aligned in a'plane corresponding to a plane movement of the respective ones of the switch brushes 36-39. According to the invention, the contact assemblies are removable from the main switch structure and may be wired into electrical circuits while separate from the general switch mechanism. The contact bank assembly is more clearly shown in Figures 3-5 of the drawings and consists of a pair of arms 70-71 of insulating material in which may be supported, as by molding, for example, the bare wire contacts 7282 and 83-93. In the preferred form of the invention being described, it is apparent that bare wire contacts 72'82 are aligned in one plane and bare wire contacts 83 93 are aligned in a second parallel plane. Since the switch being described is provided with a specific number of movable switch brushes, namely,

four, two contact bank assemblies, such as those shown in Figures 35 of the drawings, are adapted to be removably supported on the switch frame 10 in the path of movement of the switch brushes 36-39. It will be noted that the upper insulating arm 70 is provided with a cutout portion 94 and that the bare wire contacts do not extend all of the way through the cutout portion 94. This enables connecting wires to be inserted through suitable .apertures, such as shown at 95, and connected to the free end of the bare wire contact in a manner shown more clearly at 96 and 97 by Fig. 2 of the drawings.

Means is provided for removably supporting two of the contact bank assemblies, previously described in connection with Figs. 35 of the drawings, in the path of movement of the switch brushes 3639. In the drawings there is illustrated for this purpose a clip structure 100, shown in detail in Figs. 6-8 of the drawings, comprising .a base portion 101 having an upstanding end portion .102 bifurcated into two spring clip arms 103 and 104. The other end of the clip 100 is provided with an upstanding end portion 105. As shown more clearly in Figures 9 and 10 of the drawings, the removable contact bank assembly is inserted in the clip structure by passing the upper end 110 of the insulating arm 70 under ahook portio11,such as hook 111, of the bifurcated spring portion 103. A shoulder 112 molded or otherwise formed on the upper arm 70 of'the contact bank assembly engages a depending portion 113 of the hook 111 and as the contact bank assembly is insertedin the clip by moving itin the direction to the left of Fig. 9 of the drawings, the spring arm 103) is deformed from the dotted positionshown inFig- 10 t t posi i n hown in solid lines in Fig. 10 of the drawings. When the contact bank assembly has been moved to the position generally shown by Fig. 10 of the drawings, the lower shoulder 114 of the lower insulating arm 71 is received on the shoulder portions 115 of the upstanding clip portion 105. Thus, in such manner, the removable contact bank assembly 'is supported at two points, namely,

the clip shoulder engaging the bottom of the insulated arm 71 adjacent the shoulder 114 and also engaging the shoulder 112 at the upper diametrically opposed end of the bank assembly on the insulated arm 70. It will be noted, as shown in Fig. 3 of the drawings, that each of the bare wire contacts extends through the insulated support 71 to its lower surface and in order to prevent shortcircuits, the contact bank assembly must be supported in the spring clip in a manner to space the lower surface 116 of the contact assembly from the base 101 of the spring clip or the switch base frame '10. The spring clip of the invention accomplishes this function by supporting the lower right hand end of the insulated arm 71 upon the clip shoulder 115 together with the action of the end portion 113 of the spring arm 103 in engaging the shoulder 112 on the upper insulating arm 70. It should be apparent that any effort to pivot the contact bank assembly about the shoulder portion 115 in a manner to cause any portion of the lower surface 116 of the insulating arm 71 to engage the base portion 101 of the spring clip would be resisted by the spring tension of the clip arm 103 as applied to the portion 113 engaging the shoulder 112. Thus, in such manner, the removable contact bank assembly is supported at opposite ends by the spring clip with the lower surface 116 of the insulating arm 71 spaced from the base 101 of the spring clip and the switch frame 10.

It should'be-understood that various modifications may be made-in the form of the spring clip assembly for removably supporting the contact bank elements in the path of movement of the switch brushes without departingfrom the spirit of the invention. For example, nonresilient supporting means may be employed to removably support the contact bank assembly in the spaced relation to the switch frame in a manner to be engaged by the switch brushes as the switch brushes are moved during operation of the switch. Various modifications may be made within the spirit of the invention and the scope of the appended claims.

What is claimed is:

l. A switch comprising, a frame, a movable switch brush mounted on said frame, a contact bank assembly including a pair of spaced apart insulating arms, a plularity of spaced apart bare wire contact elements having respective ends terminating at and embedded in respective ones of said arms and extending transversely between said arms, and supporting means mounted on said frame for removably holding and positioning said contack bank assembly for engagement of said bare wire contacts by saidbrush as said brush is moved, said supporting means including clip means having respective elements thereof positioned to apply pressure between an end of one of said armstand the diametrically opposite end of the other arm to removably retain the portions of the arms adjacent the ends of the bare wire contacts in a spaced position with relation to the remainder of the supporting means and said frame.

2. The switch defined in claim 1, wherein said one arm includes a first shoulder-extending from said end thereof, wherein said other arm includes a second shoulder extending from said diametrically opposite end thereof, and wherein said supporting means includes a longitudinal base portion forming a guide for receiving said one arm, an upstanding portion disposed at one end of said base :;portion which includes a third shoulder for seating said end ofsaid one armin spaced relationship with said base portion and said frame and which further includes an extension oriented to abut said first shoulder, a spring arm having one end thereof attached to the other end of said base portion and having its distal end oriented to abut and apply force to said second shoulden, whereby said first shoulder is urged against said extension of said upstanding portion and said assembly is maintained in spaced relationship with respect to said base portion and said frame.

3. The switch defined in claim 2, wherein said other 10 arm includes longitudinal slot cut therethrough, one end of each of said bare Wire contact elements terminating within said slot, and the portion of said other arm above said slot having a plurality of apertures therein oriented contact elements, to the be inserted.

in cooperative relationship with the respective bare wire 15 UNITED STATES PATENTS Dunbar Nov. 15, Lienzen Feb. 28, Lienzen Dec. 31, Lindstrom Apr. 22, Sengebusch Oct. 16,

FOREIGN PATENTS Switzerland May 1,

reby enable connecting wires to 

